ABSTRACT
The other chapters in this book are concerned primarily with expertise in mental tasks. Even though an expert waiter or radiologist may use motor skills, such as speech and handwriting, the motor skills themselves are not of direct interest to most investigators. This chapter, on the other hand, is concerned with the acquisition and performance of the motor skill of typewriting. Motor skills provide a unique psychological insight, because they are the direct, concrete product of fhe large amount of mental processing required for the planning, coordination, and control of actions. From a practical standpoint, motor skills offer a unique advantage to the scientist studying expertise. Most of the interesting events in mental skills go on inside the head, and are hidden from our view. The scientist must make indirect inferences about these mental events from such data as reaction times and verbal protocols. In contrast, the normal performance of a motor skill produces an externally observable sequence of events that are directly related to the task.
